Research On The Noise Sensitive Characterization Method Of Radiation Damage In Pn Junction Material

Pn junction is the basic structure in bipolar devices, and the radiation tolerance of this structure have direct impacts on the reliability of bipolar devices operated in radiation environment. Therefore, in-depth research on the radiation effects of pn junction and to find a characterization technique which can be used to evaluate the radiation tolerance of bipolar devices are needed urgently. The low frequency noise is directly related to the inner defects of materials and devices, so noise is expected to be used as a parameter to characterize the radiation damage in pn junction material, and to become a usual nondestructive evaluative tool for the radiation tolerance of the bipolar devices.The radiation damage mechanisms and the noise generation model for pn junction materials which are widely used in semiconductor devices and integrated circuits was deeply studied, both bulk damage and surface damage exist in pn junction structure, and the latter is more important during ionizing irradiation. Under the guidance of the research method which combines the radiation effects of materials and devices, the vulnerable parts of pn junction devices were studied. According to the design principle, some test structures used to study radiation damage were designed. The irradiation experiment was designed for the samples, the electrical parameters and noise parameters were measured, and the experiment results verified the test samples and the radiation damage mechanisms. The noise sensitive characterization parameters were chosen by the comparison of the sensitivity between the electrical parameters and noise parameters to radiation damage. Based on the 1/f noise model for pn junction devices, a noise characterization model for radiation damage of pn junction material was proposed by introducing the radiation damage mechanism in 1/f noise modeling. Finally, based on the noise characterization model, the noise-sensitive characterization technique for radiation damage of pn junction material was proposed.In this paper, through the modeling for radiation damage and noise generation in pn junction material, the design of radiation damage-parameter test samples as well as the experiment results, noise sensitive characterization parameter is chosen out, a noise sensitive characterization technique for radiation damage in pn junction material was proposed, it produces a new method for the radiation tolerance evaluation of the pn junction material, technology and devices based on noise measurement.